US5116747A
Expired / Lapsed
US
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Immobilization of biologically active material in capsules prepared from a water-soluble polymer and chitosan acetate
Assignee: University of Waterloo
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Filing: 1989-08-11
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Granted: 1992-05-26
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Expires: 2009-08-11
Abstract
Abstract Biologically-active material, particularly hybridoma cells, is immobilized for mass culture in bioreactors to produce biological products, particularly monoclonal antibodies, by ionically-interacting polycationic groups on chitosan with polyanionic groups on a polyanionic water-soluble polymer. Preferably, the chitosan is chitosan acetate and the polyanionic polymer is sodium alginate. In one embodiment, droplets of a suspension of the biologically-active material and water-soluble polymer are gelled by forming a calcium salt of the water-soluble polymer to form temporary capsules, and a sequestering agent for the calcium ions is added to effect ionotropic gelation of the water-soluble polymer and chitosan to form a semi-permeable membrane around each temporary capsule. In another embodiment, porous beads are formed by exposing droplets of a suspension of the biologically active material and water-soluble polymer to an aqueous solution of chitosan and multiple cations. In a further embodiment, chitosan is added to a suspension of the biologically active material and water-soluble polymer and the resulting suspension is extruded into a solution of multi-valent anions to form a fibrous mass.
Inventors
- 👤 Murray Moo-Young
- 👤 Niels C. Bols
- 👤 Sandra E. Overgaard
- 👤 Jeno M. Scharer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:32
CPC Classifications
C; C12; C12N; C12N11/00; C12N11/02; C12N11/04; C12N5/00; C12N5/0012; C12N2533/00; C12N2533/70; C12N2533/72
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
98 words
A process for immobilizing, in the form of capsules, biologically-active material, with retained viability, which comprises: suspending said biologically-active materials in aqueous culture medium containing a water-soluble polymer having multiple anionic reactive groups that are readily ionized, forming the resulting suspension into droplets, gelling the droplets to form water-insoluble temporary capsules by forming the calcium salt of said water-soluble polymer, coating the surface of the temporary capsules with chitosan acetate, and adding a sequestering agent for the calcium ions to effect ionotropic gelation of the water-soluble polymer and chitosan acetate to form a semi-permeable membrane around each capsule.
Claim 2
Dependent Claim
98 words
A process for immobilizing, in the form of capsules, biologically-active material, with retained viability, which comprises: suspending said biologically-active materials in aqueous culture medium containing a water-soluble polymer having multiple anionic reactive groups that are readily ionized, forming the resulting suspension into droplets, gelling the droplets to form water-insoluble temporary capsules by forming the calcium salt of said water-soluble polymer, coating the surface of the temporary capsules with chitosan acetate, and adding a sequestering agent for the calcium ions to effect ionotropic gelation of the water-soluble polymer and chitosan acetate to form a semi-permeable membrane around each capsule.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein said water-soluble polymer is a polysaccharide gum.
Claim 4
Dependent Claim
12 words
The process of claim 2 wherein said polysaccharide gum is sodium alginate.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein said sequestering agent is sodium phosphate.
Claim 6
Dependent Claim
19 words
The process of claim 1 wherein said ionotropic gelation is effected at a pH of about 5.6 to 6.0.
Claim 7
Dependent Claim
46 words
The process of claim 1 wherein said biological-active material produces biological substances and said semi-permeable membrane has a permeability to permit nutrients and oxygen to flow from a bulk active medium to the biological material and such biological substances to flow into the bulk active medium.
Claim 8
Dependent Claim
44 words
The process of claim 1 wherein said biologically-active material produces biological substances and said semipermeable membrane has a permeability to permit nutrients and oxygen to flow from a bulk active medium to the biological material and to retain the biological material within the microcapsule.
Claim 9
Dependent Claim
12 words
The process of claim 1 wherein said biological material is hybridoma cells.
Claim 10
Dependent Claim
11 words
The process of claim 1 wherein said biologically-active material is cells.
Claim 11
Dependent Claim
95 words
A process for immobilizing biologically-active material in the form of porous beads, with retained viability, which comprises: suspending the biologically-active material in an aqueous culture medium containing a water-soluble polymer having multiple ionic reactive groups, forming the resulting suspension into droplets, and exposing said droplets to an aqueous solution containing (i) chitosan acetate and (ii) multiple counter-ions at a pH of about 5.6 to 6.0, whereby said chitosan acetate and said multiple counter-ions compete for ionic sites on the water-soluble polymer to form porous beads in which the biological material is impregnated within the pores.
Claim 12
Dependent Claim
95 words
A process for immobilizing biologically-active material in the form of porous beads, with retained viability, which comprises: suspending the biologically-active material in an aqueous culture medium containing a water-soluble polymer having multiple ionic reactive groups, forming the resulting suspension into droplets, and exposing said droplets to an aqueous solution containing (i) chitosan acetate and (ii) multiple counter-ions at a pH of about 5.6 to 6.0, whereby said chitosan acetate and said multiple counter-ions compete for ionic sites on the water-soluble polymer to form porous beads in which the biological material is impregnated within the pores.
Claim 13
Dependent Claim
12 words
The process of claim 1 wherein said water-soluble polymer is a polysaccharide.
Claim 14
Dependent Claim
11 words
The process of claim 11 wherein said polysaccharide is sodium alginate.
Claim 15
Dependent Claim
18 words
The process of claim 11 wherein said source of multiple counter-ions in said aqueous solution is calcium chloride.
Claim 16
Dependent Claim
12 words
The process of claim 11 wherein said biologically-active material is hybridoma cells.
Claim 17
Dependent Claim
11 words
The process of claim 10 wherein said biologically-active material is cells.
Claim 18
Dependent Claim
67 words
A process for immobilizing, in the form of porous fibers, biologically-active material with retained viability, which comprises: suspending the biologically-active material in a physiologically-compatible medium containing a water-soluble polymer with multiple anionic moieties, adding chitosan acetate to the resulting suspension to form a polyelectric complex with the water-soluble polymer, and extruding the resulting suspension into an aqueous cross-linking solution containing multi-valent anions to form a fibrous mass.
Claim 19
Dependent Claim
67 words
A process for immobilizing, in the form of porous fibers, biologically-active material with retained viability, which comprises: suspending the biologically-active material in a physiologically-compatible medium containing a water-soluble polymer with multiple anionic moieties, adding chitosan acetate to the resulting suspension to form a polyelectric complex with the water-soluble polymer, and extruding the resulting suspension into an aqueous cross-linking solution containing multi-valent anions to form a fibrous mass.
Claim 20
Dependent Claim
13 words
The process of claim 16 wherein said water-soluble polymer is a polysaccharide gum.
Claim 21
Dependent Claim
12 words
The process of claim 17 wherein said polysaccharide gum is sodium alginate.
Claim 22
Dependent Claim
18 words
The process of claim 16 wherein said multivalent anions in said cross-linking solution are provided by sodium pyrophosphate.
Claim 23
Dependent Claim
19 words
The process of claim 16 wherein said polyelectric complex is formed at a pH of about 5.6 to 6.0.
Claim 24
Dependent Claim
18 words
The process of claim 20 wherein said aqueous cross-linking solution has a pH of about 7.2 to 7.4.
Claim 25
Dependent Claim
12 words
The process of claim 16 wherein said biological material is hybridoma cells.
Claim 26
Dependent Claim
12 words
The process of claim 16 wherein said biologically active material is cells.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-05-26 | 1995-11-25 | 1996-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-26 | 1999-11-25 | 2000-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-26 | 2003-11-25 | 2004-05-26 | $7700.00 | Window Closed / Lapsed |